Wi-Fi calling when you are in a mobile blackspot (Important information)

Following November 2022 negotiations with Telcos, Wi-Fi calling is now available from selected Mobile Virtual Network Operators (MVNOs), so you can make and receive calls in a mobile blackspot. That includes SMS and video calls.

The information is provided as is, where is. You should contact your MVNO if it does not work for you.

What is Wi-Fi calling?

Many smartphones have a feature that allows you to make or receive a call using home or office Wi-Fi by ‘tunnelling’ the call from or to your network provider. Yes, you can make and receive calls over Wi-Fi. Voice does not take much bandwidth – 100-120 kbps or 45MB/hr.

In essence, any Apple iPhone from 6, Samsung Galaxy from S7, Google Pixel from 4, OPPO Find (and many Reno and A-series) and recent Motorola G and Edge series should have it.

In Android, look under Settings>Mobile Network>Sim1> Enable Wi-Fi calling. If you are having issues, search for your phone’s make and model and Wi-Fi calling.

In iPhone, go to Settings>Phone>Wi-Fi Calling.

If you move out of Wi-Fi range, the phone automatically switches to mobile data with no dropped calls.

How do you know you are using Wi-Fi calling?

You should see a VoLTE icon in your phone’s status bar. VoLTE simply means making a digital call instead of the analogue 3G network. It is sometimes called VoWiFi (voice over Wi-Fi). Some phones have a dedicated Wi-Fi calling icon.

And Wi-Fi calling only kicks in when the Mobile signal strength is too low. If you live in a good reception area, by all means, enable it, but you may never use it.

Any up-or-down-sides?

The upsides include

Making and receiving free calls/text/video calls in mobile blackspots.
Should work over Satellite broadband services (like StarLink).
Can have perceptibly better voice quality.
Should not use your Mobile Data – it uses IMS APN for data that carries signalling and voice.
Should work with pre-and-post-paid plans (depending on the MVNO).
Saves battery.
Can use Public Wi-Fi if the signal is strong enough.
Supports 000 emergency calls (but your location may not be precise).
International roaming is generally supported (depending on the carrier), but you can use VoIP Apps like Google Duo etc., over Wi-Fi anyway.

The downsides – more caveats are

At least a 25/5Mbps NBN internet connection (via an NBN reseller – it does not have to be with Telstra, Vodafone, or Optus)
Reliable internet (and it is most of the time)
Decent whole-of-home Wi-Fi coverage, preferably using Wi-Fi 5 AC or 6 AX and the 5GHz band, although 2.4GHz is fine too.
You may have to enter the area code if it cannot find a number.
You may have to change router settings to allow IPsec passthrough and Certificate Fragmentation support. Most modern routers default to this.